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diff --git a/intl/icu/source/common/unicode/ubidi.h b/intl/icu/source/common/unicode/ubidi.h new file mode 100644 index 0000000000..536f4172bc --- /dev/null +++ b/intl/icu/source/common/unicode/ubidi.h @@ -0,0 +1,2211 @@ +// © 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +****************************************************************************** +* +* Copyright (C) 1999-2013, International Business Machines +* Corporation and others. All Rights Reserved. +* +****************************************************************************** +* file name: ubidi.h +* encoding: UTF-8 +* tab size: 8 (not used) +* indentation:4 +* +* created on: 1999jul27 +* created by: Markus W. Scherer, updated by Matitiahu Allouche +*/ + +#ifndef UBIDI_H +#define UBIDI_H + +#include "unicode/utypes.h" +#include "unicode/uchar.h" + +#if U_SHOW_CPLUSPLUS_API +#include "unicode/localpointer.h" +#endif // U_SHOW_CPLUSPLUS_API + +/** + *\file + * \brief C API: Bidi algorithm + * + * <h2>Bidi algorithm for ICU</h2> + * + * This is an implementation of the Unicode Bidirectional Algorithm. + * The algorithm is defined in the + * <a href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Annex #9</a>.<p> + * + * Note: Libraries that perform a bidirectional algorithm and + * reorder strings accordingly are sometimes called "Storage Layout Engines". + * ICU's Bidi and shaping (u_shapeArabic()) APIs can be used at the core of such + * "Storage Layout Engines". + * + * <h3>General remarks about the API:</h3> + * + * In functions with an error code parameter, + * the <code>pErrorCode</code> pointer must be valid + * and the value that it points to must not indicate a failure before + * the function call. Otherwise, the function returns immediately. + * After the function call, the value indicates success or failure.<p> + * + * The "limit" of a sequence of characters is the position just after their + * last character, i.e., one more than that position.<p> + * + * Some of the API functions provide access to "runs". + * Such a "run" is defined as a sequence of characters + * that are at the same embedding level + * after performing the Bidi algorithm.<p> + * + * @author Markus W. Scherer + * @version 1.0 + * + * + * <h4> Sample code for the ICU Bidi API </h4> + * + * <h5>Rendering a paragraph with the ICU Bidi API</h5> + * + * This is (hypothetical) sample code that illustrates + * how the ICU Bidi API could be used to render a paragraph of text. + * Rendering code depends highly on the graphics system, + * therefore this sample code must make a lot of assumptions, + * which may or may not match any existing graphics system's properties. + * + * <p>The basic assumptions are:</p> + * <ul> + * <li>Rendering is done from left to right on a horizontal line.</li> + * <li>A run of single-style, unidirectional text can be rendered at once.</li> + * <li>Such a run of text is passed to the graphics system with + * characters (code units) in logical order.</li> + * <li>The line-breaking algorithm is very complicated + * and Locale-dependent - + * and therefore its implementation omitted from this sample code.</li> + * </ul> + * + * <pre> + * \code + *#include <unicode/ubidi.h> + * + *typedef enum { + * styleNormal=0, styleSelected=1, + * styleBold=2, styleItalics=4, + * styleSuper=8, styleSub=16 + *} Style; + * + *typedef struct { int32_t limit; Style style; } StyleRun; + * + *int getTextWidth(const UChar *text, int32_t start, int32_t limit, + * const StyleRun *styleRuns, int styleRunCount); + * + * // set *pLimit and *pStyleRunLimit for a line + * // from text[start] and from styleRuns[styleRunStart] + * // using ubidi_getLogicalRun(para, ...) + *void getLineBreak(const UChar *text, int32_t start, int32_t *pLimit, + * UBiDi *para, + * const StyleRun *styleRuns, int styleRunStart, int *pStyleRunLimit, + * int *pLineWidth); + * + * // render runs on a line sequentially, always from left to right + * + * // prepare rendering a new line + * void startLine(UBiDiDirection textDirection, int lineWidth); + * + * // render a run of text and advance to the right by the run width + * // the text[start..limit-1] is always in logical order + * void renderRun(const UChar *text, int32_t start, int32_t limit, + * UBiDiDirection textDirection, Style style); + * + * // We could compute a cross-product + * // from the style runs with the directional runs + * // and then reorder it. + * // Instead, here we iterate over each run type + * // and render the intersections - + * // with shortcuts in simple (and common) cases. + * // renderParagraph() is the main function. + * + * // render a directional run with + * // (possibly) multiple style runs intersecting with it + * void renderDirectionalRun(const UChar *text, + * int32_t start, int32_t limit, + * UBiDiDirection direction, + * const StyleRun *styleRuns, int styleRunCount) { + * int i; + * + * // iterate over style runs + * if(direction==UBIDI_LTR) { + * int styleLimit; + * + * for(i=0; i<styleRunCount; ++i) { + * styleLimit=styleRuns[i].limit; + * if(start<styleLimit) { + * if(styleLimit>limit) { styleLimit=limit; } + * renderRun(text, start, styleLimit, + * direction, styleRuns[i].style); + * if(styleLimit==limit) { break; } + * start=styleLimit; + * } + * } + * } else { + * int styleStart; + * + * for(i=styleRunCount-1; i>=0; --i) { + * if(i>0) { + * styleStart=styleRuns[i-1].limit; + * } else { + * styleStart=0; + * } + * if(limit>=styleStart) { + * if(styleStart<start) { styleStart=start; } + * renderRun(text, styleStart, limit, + * direction, styleRuns[i].style); + * if(styleStart==start) { break; } + * limit=styleStart; + * } + * } + * } + * } + * + * // the line object represents text[start..limit-1] + * void renderLine(UBiDi *line, const UChar *text, + * int32_t start, int32_t limit, + * const StyleRun *styleRuns, int styleRunCount, + * UErrorCode *pErrorCode) { + * UBiDiDirection direction=ubidi_getDirection(line); + * if(direction!=UBIDI_MIXED) { + * // unidirectional + * if(styleRunCount<=1) { + * renderRun(text, start, limit, direction, styleRuns[0].style); + * } else { + * renderDirectionalRun(text, start, limit, + * direction, styleRuns, styleRunCount); + * } + * } else { + * // mixed-directional + * int32_t count, i, length; + * UBiDiLevel level; + * + * count=ubidi_countRuns(line, pErrorCode); + * if(U_SUCCESS(*pErrorCode)) { + * if(styleRunCount<=1) { + * Style style=styleRuns[0].style; + * + * // iterate over directional runs + * for(i=0; i<count; ++i) { + * direction=ubidi_getVisualRun(line, i, &start, &length); + * renderRun(text, start, start+length, direction, style); + * } + * } else { + * int32_t j; + * + * // iterate over both directional and style runs + * for(i=0; i<count; ++i) { + * direction=ubidi_getVisualRun(line, i, &start, &length); + * renderDirectionalRun(text, start, start+length, + * direction, styleRuns, styleRunCount); + * } + * } + * } + * } + * } + * + *void renderParagraph(const UChar *text, int32_t length, + * UBiDiDirection textDirection, + * const StyleRun *styleRuns, int styleRunCount, + * int lineWidth, + * UErrorCode *pErrorCode) { + * UBiDi *para; + * + * if(pErrorCode==NULL || U_FAILURE(*pErrorCode) || length<=0) { + * return; + * } + * + * para=ubidi_openSized(length, 0, pErrorCode); + * if(para==NULL) { return; } + * + * ubidi_setPara(para, text, length, + * textDirection ? UBIDI_DEFAULT_RTL : UBIDI_DEFAULT_LTR, + * NULL, pErrorCode); + * if(U_SUCCESS(*pErrorCode)) { + * UBiDiLevel paraLevel=1&ubidi_getParaLevel(para); + * StyleRun styleRun={ length, styleNormal }; + * int width; + * + * if(styleRuns==NULL || styleRunCount<=0) { + * styleRunCount=1; + * styleRuns=&styleRun; + * } + * + * // assume styleRuns[styleRunCount-1].limit>=length + * + * width=getTextWidth(text, 0, length, styleRuns, styleRunCount); + * if(width<=lineWidth) { + * // everything fits onto one line + * + * // prepare rendering a new line from either left or right + * startLine(paraLevel, width); + * + * renderLine(para, text, 0, length, + * styleRuns, styleRunCount, pErrorCode); + * } else { + * UBiDi *line; + * + * // we need to render several lines + * line=ubidi_openSized(length, 0, pErrorCode); + * if(line!=NULL) { + * int32_t start=0, limit; + * int styleRunStart=0, styleRunLimit; + * + * for(;;) { + * limit=length; + * styleRunLimit=styleRunCount; + * getLineBreak(text, start, &limit, para, + * styleRuns, styleRunStart, &styleRunLimit, + * &width); + * ubidi_setLine(para, start, limit, line, pErrorCode); + * if(U_SUCCESS(*pErrorCode)) { + * // prepare rendering a new line + * // from either left or right + * startLine(paraLevel, width); + * + * renderLine(line, text, start, limit, + * styleRuns+styleRunStart, + * styleRunLimit-styleRunStart, pErrorCode); + * } + * if(limit==length) { break; } + * start=limit; + * styleRunStart=styleRunLimit-1; + * if(start>=styleRuns[styleRunStart].limit) { + * ++styleRunStart; + * } + * } + * + * ubidi_close(line); + * } + * } + * } + * + * ubidi_close(para); + *} + *\endcode + * </pre> + */ + +/*DOCXX_TAG*/ +/*@{*/ + +/** + * UBiDiLevel is the type of the level values in this + * Bidi implementation. + * It holds an embedding level and indicates the visual direction + * by its bit 0 (even/odd value).<p> + * + * It can also hold non-level values for the + * <code>paraLevel</code> and <code>embeddingLevels</code> + * arguments of <code>ubidi_setPara()</code>; there: + * <ul> + * <li>bit 7 of an <code>embeddingLevels[]</code> + * value indicates whether the using application is + * specifying the level of a character to <i>override</i> whatever the + * Bidi implementation would resolve it to.</li> + * <li><code>paraLevel</code> can be set to the + * pseudo-level values <code>UBIDI_DEFAULT_LTR</code> + * and <code>UBIDI_DEFAULT_RTL</code>.</li> + * </ul> + * + * @see ubidi_setPara + * + * <p>The related constants are not real, valid level values. + * <code>UBIDI_DEFAULT_XXX</code> can be used to specify + * a default for the paragraph level for + * when the <code>ubidi_setPara()</code> function + * shall determine it but there is no + * strongly typed character in the input.<p> + * + * Note that the value for <code>UBIDI_DEFAULT_LTR</code> is even + * and the one for <code>UBIDI_DEFAULT_RTL</code> is odd, + * just like with normal LTR and RTL level values - + * these special values are designed that way. Also, the implementation + * assumes that UBIDI_MAX_EXPLICIT_LEVEL is odd. + * + * Note: The numeric values of the related constants will not change: + * They are tied to the use of 7-bit byte values (plus the override bit) + * and of the UBiDiLevel=uint8_t data type in this API. + * + * @see UBIDI_DEFAULT_LTR + * @see UBIDI_DEFAULT_RTL + * @see UBIDI_LEVEL_OVERRIDE + * @see UBIDI_MAX_EXPLICIT_LEVEL + * @stable ICU 2.0 + */ +typedef uint8_t UBiDiLevel; + +/** Paragraph level setting.<p> + * + * Constant indicating that the base direction depends on the first strong + * directional character in the text according to the Unicode Bidirectional + * Algorithm. If no strong directional character is present, + * then set the paragraph level to 0 (left-to-right).<p> + * + * If this value is used in conjunction with reordering modes + * <code>UBIDI_REORDER_INVERSE_LIKE_DIRECT</code> or + * <code>UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code>, the text to reorder + * is assumed to be visual LTR, and the text after reordering is required + * to be the corresponding logical string with appropriate contextual + * direction. The direction of the result string will be RTL if either + * the righmost or leftmost strong character of the source text is RTL + * or Arabic Letter, the direction will be LTR otherwise.<p> + * + * If reordering option <code>UBIDI_OPTION_INSERT_MARKS</code> is set, an RLM may + * be added at the beginning of the result string to ensure round trip + * (that the result string, when reordered back to visual, will produce + * the original source text). + * @see UBIDI_REORDER_INVERSE_LIKE_DIRECT + * @see UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL + * @stable ICU 2.0 + */ +#define UBIDI_DEFAULT_LTR 0xfe + +/** Paragraph level setting.<p> + * + * Constant indicating that the base direction depends on the first strong + * directional character in the text according to the Unicode Bidirectional + * Algorithm. If no strong directional character is present, + * then set the paragraph level to 1 (right-to-left).<p> + * + * If this value is used in conjunction with reordering modes + * <code>UBIDI_REORDER_INVERSE_LIKE_DIRECT</code> or + * <code>UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code>, the text to reorder + * is assumed to be visual LTR, and the text after reordering is required + * to be the corresponding logical string with appropriate contextual + * direction. The direction of the result string will be RTL if either + * the righmost or leftmost strong character of the source text is RTL + * or Arabic Letter, or if the text contains no strong character; + * the direction will be LTR otherwise.<p> + * + * If reordering option <code>UBIDI_OPTION_INSERT_MARKS</code> is set, an RLM may + * be added at the beginning of the result string to ensure round trip + * (that the result string, when reordered back to visual, will produce + * the original source text). + * @see UBIDI_REORDER_INVERSE_LIKE_DIRECT + * @see UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL + * @stable ICU 2.0 + */ +#define UBIDI_DEFAULT_RTL 0xff + +/** + * Maximum explicit embedding level. + * Same as the max_depth value in the + * <a href="http://www.unicode.org/reports/tr9/#BD2">Unicode Bidirectional Algorithm</a>. + * (The maximum resolved level can be up to <code>UBIDI_MAX_EXPLICIT_LEVEL+1</code>). + * @stable ICU 2.0 + */ +#define UBIDI_MAX_EXPLICIT_LEVEL 125 + +/** Bit flag for level input. + * Overrides directional properties. + * @stable ICU 2.0 + */ +#define UBIDI_LEVEL_OVERRIDE 0x80 + +/** + * Special value which can be returned by the mapping functions when a logical + * index has no corresponding visual index or vice-versa. This may happen + * for the logical-to-visual mapping of a Bidi control when option + * <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> is specified. This can also happen + * for the visual-to-logical mapping of a Bidi mark (LRM or RLM) inserted + * by option <code>#UBIDI_OPTION_INSERT_MARKS</code>. + * @see ubidi_getVisualIndex + * @see ubidi_getVisualMap + * @see ubidi_getLogicalIndex + * @see ubidi_getLogicalMap + * @stable ICU 3.6 + */ +#define UBIDI_MAP_NOWHERE (-1) + +/** + * <code>UBiDiDirection</code> values indicate the text direction. + * @stable ICU 2.0 + */ +enum UBiDiDirection { + /** Left-to-right text. This is a 0 value. + * <ul> + * <li>As return value for <code>ubidi_getDirection()</code>, it means + * that the source string contains no right-to-left characters, or + * that the source string is empty and the paragraph level is even. + * <li> As return value for <code>ubidi_getBaseDirection()</code>, it + * means that the first strong character of the source string has + * a left-to-right direction. + * </ul> + * @stable ICU 2.0 + */ + UBIDI_LTR, + /** Right-to-left text. This is a 1 value. + * <ul> + * <li>As return value for <code>ubidi_getDirection()</code>, it means + * that the source string contains no left-to-right characters, or + * that the source string is empty and the paragraph level is odd. + * <li> As return value for <code>ubidi_getBaseDirection()</code>, it + * means that the first strong character of the source string has + * a right-to-left direction. + * </ul> + * @stable ICU 2.0 + */ + UBIDI_RTL, + /** Mixed-directional text. + * <p>As return value for <code>ubidi_getDirection()</code>, it means + * that the source string contains both left-to-right and + * right-to-left characters. + * @stable ICU 2.0 + */ + UBIDI_MIXED, + /** No strongly directional text. + * <p>As return value for <code>ubidi_getBaseDirection()</code>, it means + * that the source string is missing or empty, or contains neither left-to-right + * nor right-to-left characters. + * @stable ICU 4.6 + */ + UBIDI_NEUTRAL +}; + +/** @stable ICU 2.0 */ +typedef enum UBiDiDirection UBiDiDirection; + +/** + * Forward declaration of the <code>UBiDi</code> structure for the declaration of + * the API functions. Its fields are implementation-specific.<p> + * This structure holds information about a paragraph (or multiple paragraphs) + * of text with Bidi-algorithm-related details, or about one line of + * such a paragraph.<p> + * Reordering can be done on a line, or on one or more paragraphs which are + * then interpreted each as one single line. + * @stable ICU 2.0 + */ +struct UBiDi; + +/** @stable ICU 2.0 */ +typedef struct UBiDi UBiDi; + +/** + * Allocate a <code>UBiDi</code> structure. + * Such an object is initially empty. It is assigned + * the Bidi properties of a piece of text containing one or more paragraphs + * by <code>ubidi_setPara()</code> + * or the Bidi properties of a line within a paragraph by + * <code>ubidi_setLine()</code>.<p> + * This object can be reused for as long as it is not deallocated + * by calling <code>ubidi_close()</code>.<p> + * <code>ubidi_setPara()</code> and <code>ubidi_setLine()</code> will allocate + * additional memory for internal structures as necessary. + * + * @return An empty <code>UBiDi</code> object. + * @stable ICU 2.0 + */ +U_CAPI UBiDi * U_EXPORT2 +ubidi_open(void); + +/** + * Allocate a <code>UBiDi</code> structure with preallocated memory + * for internal structures. + * This function provides a <code>UBiDi</code> object like <code>ubidi_open()</code> + * with no arguments, but it also preallocates memory for internal structures + * according to the sizings supplied by the caller.<p> + * Subsequent functions will not allocate any more memory, and are thus + * guaranteed not to fail because of lack of memory.<p> + * The preallocation can be limited to some of the internal memory + * by setting some values to 0 here. That means that if, e.g., + * <code>maxRunCount</code> cannot be reasonably predetermined and should not + * be set to <code>maxLength</code> (the only failproof value) to avoid + * wasting memory, then <code>maxRunCount</code> could be set to 0 here + * and the internal structures that are associated with it will be allocated + * on demand, just like with <code>ubidi_open()</code>. + * + * @param maxLength is the maximum text or line length that internal memory + * will be preallocated for. An attempt to associate this object with a + * longer text will fail, unless this value is 0, which leaves the allocation + * up to the implementation. + * + * @param maxRunCount is the maximum anticipated number of same-level runs + * that internal memory will be preallocated for. An attempt to access + * visual runs on an object that was not preallocated for as many runs + * as the text was actually resolved to will fail, + * unless this value is 0, which leaves the allocation up to the implementation.<br><br> + * The number of runs depends on the actual text and maybe anywhere between + * 1 and <code>maxLength</code>. It is typically small. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @return An empty <code>UBiDi</code> object with preallocated memory. + * @stable ICU 2.0 + */ +U_CAPI UBiDi * U_EXPORT2 +ubidi_openSized(int32_t maxLength, int32_t maxRunCount, UErrorCode *pErrorCode); + +/** + * <code>ubidi_close()</code> must be called to free the memory + * associated with a UBiDi object.<p> + * + * <strong>Important: </strong> + * A parent <code>UBiDi</code> object must not be destroyed or reused if + * it still has children. + * If a <code>UBiDi</code> object has become the <i>child</i> + * of another one (its <i>parent</i>) by calling + * <code>ubidi_setLine()</code>, then the child object must + * be destroyed (closed) or reused (by calling + * <code>ubidi_setPara()</code> or <code>ubidi_setLine()</code>) + * before the parent object. + * + * @param pBiDi is a <code>UBiDi</code> object. + * + * @see ubidi_setPara + * @see ubidi_setLine + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_close(UBiDi *pBiDi); + +#if U_SHOW_CPLUSPLUS_API + +U_NAMESPACE_BEGIN + +/** + * \class LocalUBiDiPointer + * "Smart pointer" class, closes a UBiDi via ubidi_close(). + * For most methods see the LocalPointerBase base class. + * + * @see LocalPointerBase + * @see LocalPointer + * @stable ICU 4.4 + */ +U_DEFINE_LOCAL_OPEN_POINTER(LocalUBiDiPointer, UBiDi, ubidi_close); + +U_NAMESPACE_END + +#endif + +/** + * Modify the operation of the Bidi algorithm such that it + * approximates an "inverse Bidi" algorithm. This function + * must be called before <code>ubidi_setPara()</code>. + * + * <p>The normal operation of the Bidi algorithm as described + * in the Unicode Technical Report is to take text stored in logical + * (keyboard, typing) order and to determine the reordering of it for visual + * rendering. + * Some legacy systems store text in visual order, and for operations + * with standard, Unicode-based algorithms, the text needs to be transformed + * to logical order. This is effectively the inverse algorithm of the + * described Bidi algorithm. Note that there is no standard algorithm for + * this "inverse Bidi" and that the current implementation provides only an + * approximation of "inverse Bidi".</p> + * + * <p>With <code>isInverse</code> set to <code>true</code>, + * this function changes the behavior of some of the subsequent functions + * in a way that they can be used for the inverse Bidi algorithm. + * Specifically, runs of text with numeric characters will be treated in a + * special way and may need to be surrounded with LRM characters when they are + * written in reordered sequence.</p> + * + * <p>Output runs should be retrieved using <code>ubidi_getVisualRun()</code>. + * Since the actual input for "inverse Bidi" is visually ordered text and + * <code>ubidi_getVisualRun()</code> gets the reordered runs, these are actually + * the runs of the logically ordered output.</p> + * + * <p>Calling this function with argument <code>isInverse</code> set to + * <code>true</code> is equivalent to calling + * <code>ubidi_setReorderingMode</code> with argument + * <code>reorderingMode</code> + * set to <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>.<br> + * Calling this function with argument <code>isInverse</code> set to + * <code>false</code> is equivalent to calling + * <code>ubidi_setReorderingMode</code> with argument + * <code>reorderingMode</code> + * set to <code>#UBIDI_REORDER_DEFAULT</code>. + * + * @param pBiDi is a <code>UBiDi</code> object. + * + * @param isInverse specifies "forward" or "inverse" Bidi operation. + * + * @see ubidi_setPara + * @see ubidi_writeReordered + * @see ubidi_setReorderingMode + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_setInverse(UBiDi *pBiDi, UBool isInverse); + +/** + * Is this Bidi object set to perform the inverse Bidi algorithm? + * <p>Note: calling this function after setting the reordering mode with + * <code>ubidi_setReorderingMode</code> will return <code>true</code> if the + * reordering mode was set to <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>, + * <code>false</code> for all other values.</p> + * + * @param pBiDi is a <code>UBiDi</code> object. + * @return true if the Bidi object is set to perform the inverse Bidi algorithm + * by handling numbers as L. + * + * @see ubidi_setInverse + * @see ubidi_setReorderingMode + * @stable ICU 2.0 + */ + +U_CAPI UBool U_EXPORT2 +ubidi_isInverse(UBiDi *pBiDi); + +/** + * Specify whether block separators must be allocated level zero, + * so that successive paragraphs will progress from left to right. + * This function must be called before <code>ubidi_setPara()</code>. + * Paragraph separators (B) may appear in the text. Setting them to level zero + * means that all paragraph separators (including one possibly appearing + * in the last text position) are kept in the reordered text after the text + * that they follow in the source text. + * When this feature is not enabled, a paragraph separator at the last + * position of the text before reordering will go to the first position + * of the reordered text when the paragraph level is odd. + * + * @param pBiDi is a <code>UBiDi</code> object. + * + * @param orderParagraphsLTR specifies whether paragraph separators (B) must + * receive level 0, so that successive paragraphs progress from left to right. + * + * @see ubidi_setPara + * @stable ICU 3.4 + */ +U_CAPI void U_EXPORT2 +ubidi_orderParagraphsLTR(UBiDi *pBiDi, UBool orderParagraphsLTR); + +/** + * Is this Bidi object set to allocate level 0 to block separators so that + * successive paragraphs progress from left to right? + * + * @param pBiDi is a <code>UBiDi</code> object. + * @return true if the Bidi object is set to allocate level 0 to block + * separators. + * + * @see ubidi_orderParagraphsLTR + * @stable ICU 3.4 + */ +U_CAPI UBool U_EXPORT2 +ubidi_isOrderParagraphsLTR(UBiDi *pBiDi); + +/** + * <code>UBiDiReorderingMode</code> values indicate which variant of the Bidi + * algorithm to use. + * + * @see ubidi_setReorderingMode + * @stable ICU 3.6 + */ +typedef enum UBiDiReorderingMode { + /** Regular Logical to Visual Bidi algorithm according to Unicode. + * This is a 0 value. + * @stable ICU 3.6 */ + UBIDI_REORDER_DEFAULT = 0, + /** Logical to Visual algorithm which handles numbers in a way which + * mimics the behavior of Windows XP. + * @stable ICU 3.6 */ + UBIDI_REORDER_NUMBERS_SPECIAL, + /** Logical to Visual algorithm grouping numbers with adjacent R characters + * (reversible algorithm). + * @stable ICU 3.6 */ + UBIDI_REORDER_GROUP_NUMBERS_WITH_R, + /** Reorder runs only to transform a Logical LTR string to the Logical RTL + * string with the same display, or vice-versa.<br> + * If this mode is set together with option + * <code>#UBIDI_OPTION_INSERT_MARKS</code>, some Bidi controls in the source + * text may be removed and other controls may be added to produce the + * minimum combination which has the required display. + * @stable ICU 3.6 */ + UBIDI_REORDER_RUNS_ONLY, + /** Visual to Logical algorithm which handles numbers like L + * (same algorithm as selected by <code>ubidi_setInverse(true)</code>. + * @see ubidi_setInverse + * @stable ICU 3.6 */ + UBIDI_REORDER_INVERSE_NUMBERS_AS_L, + /** Visual to Logical algorithm equivalent to the regular Logical to Visual + * algorithm. + * @stable ICU 3.6 */ + UBIDI_REORDER_INVERSE_LIKE_DIRECT, + /** Inverse Bidi (Visual to Logical) algorithm for the + * <code>UBIDI_REORDER_NUMBERS_SPECIAL</code> Bidi algorithm. + * @stable ICU 3.6 */ + UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL, +#ifndef U_HIDE_DEPRECATED_API + /** + * Number of values for reordering mode. + * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420. + */ + UBIDI_REORDER_COUNT +#endif // U_HIDE_DEPRECATED_API +} UBiDiReorderingMode; + +/** + * Modify the operation of the Bidi algorithm such that it implements some + * variant to the basic Bidi algorithm or approximates an "inverse Bidi" + * algorithm, depending on different values of the "reordering mode". + * This function must be called before <code>ubidi_setPara()</code>, and stays + * in effect until called again with a different argument. + * + * <p>The normal operation of the Bidi algorithm as described + * in the Unicode Standard Annex #9 is to take text stored in logical + * (keyboard, typing) order and to determine how to reorder it for visual + * rendering.</p> + * + * <p>With the reordering mode set to a value other than + * <code>#UBIDI_REORDER_DEFAULT</code>, this function changes the behavior of + * some of the subsequent functions in a way such that they implement an + * inverse Bidi algorithm or some other algorithm variants.</p> + * + * <p>Some legacy systems store text in visual order, and for operations + * with standard, Unicode-based algorithms, the text needs to be transformed + * into logical order. This is effectively the inverse algorithm of the + * described Bidi algorithm. Note that there is no standard algorithm for + * this "inverse Bidi", so a number of variants are implemented here.</p> + * + * <p>In other cases, it may be desirable to emulate some variant of the + * Logical to Visual algorithm (e.g. one used in MS Windows), or perform a + * Logical to Logical transformation.</p> + * + * <ul> + * <li>When the reordering mode is set to <code>#UBIDI_REORDER_DEFAULT</code>, + * the standard Bidi Logical to Visual algorithm is applied.</li> + * + * <li>When the reordering mode is set to + * <code>#UBIDI_REORDER_NUMBERS_SPECIAL</code>, + * the algorithm used to perform Bidi transformations when calling + * <code>ubidi_setPara</code> should approximate the algorithm used in + * Microsoft Windows XP rather than strictly conform to the Unicode Bidi + * algorithm. + * <br> + * The differences between the basic algorithm and the algorithm addressed + * by this option are as follows: + * <ul> + * <li>Within text at an even embedding level, the sequence "123AB" + * (where AB represent R or AL letters) is transformed to "123BA" by the + * Unicode algorithm and to "BA123" by the Windows algorithm.</li> + * <li>Arabic-Indic numbers (AN) are handled by the Windows algorithm just + * like regular numbers (EN).</li> + * </ul></li> + * + * <li>When the reordering mode is set to + * <code>#UBIDI_REORDER_GROUP_NUMBERS_WITH_R</code>, + * numbers located between LTR text and RTL text are associated with the RTL + * text. For instance, an LTR paragraph with content "abc 123 DEF" (where + * upper case letters represent RTL characters) will be transformed to + * "abc FED 123" (and not "abc 123 FED"), "DEF 123 abc" will be transformed + * to "123 FED abc" and "123 FED abc" will be transformed to "DEF 123 abc". + * This makes the algorithm reversible and makes it useful when round trip + * (from visual to logical and back to visual) must be achieved without + * adding LRM characters. However, this is a variation from the standard + * Unicode Bidi algorithm.<br> + * The source text should not contain Bidi control characters other than LRM + * or RLM.</li> + * + * <li>When the reordering mode is set to + * <code>#UBIDI_REORDER_RUNS_ONLY</code>, + * a "Logical to Logical" transformation must be performed: + * <ul> + * <li>If the default text level of the source text (argument <code>paraLevel</code> + * in <code>ubidi_setPara</code>) is even, the source text will be handled as + * LTR logical text and will be transformed to the RTL logical text which has + * the same LTR visual display.</li> + * <li>If the default level of the source text is odd, the source text + * will be handled as RTL logical text and will be transformed to the + * LTR logical text which has the same LTR visual display.</li> + * </ul> + * This mode may be needed when logical text which is basically Arabic or + * Hebrew, with possible included numbers or phrases in English, has to be + * displayed as if it had an even embedding level (this can happen if the + * displaying application treats all text as if it was basically LTR). + * <br> + * This mode may also be needed in the reverse case, when logical text which is + * basically English, with possible included phrases in Arabic or Hebrew, has to + * be displayed as if it had an odd embedding level. + * <br> + * Both cases could be handled by adding LRE or RLE at the head of the text, + * if the display subsystem supports these formatting controls. If it does not, + * the problem may be handled by transforming the source text in this mode + * before displaying it, so that it will be displayed properly.<br> + * The source text should not contain Bidi control characters other than LRM + * or RLM.</li> + * + * <li>When the reordering mode is set to + * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>, an "inverse Bidi" algorithm + * is applied. + * Runs of text with numeric characters will be treated like LTR letters and + * may need to be surrounded with LRM characters when they are written in + * reordered sequence (the option <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code> can + * be used with function <code>ubidi_writeReordered</code> to this end. This + * mode is equivalent to calling <code>ubidi_setInverse()</code> with + * argument <code>isInverse</code> set to <code>true</code>.</li> + * + * <li>When the reordering mode is set to + * <code>#UBIDI_REORDER_INVERSE_LIKE_DIRECT</code>, the "direct" Logical to Visual + * Bidi algorithm is used as an approximation of an "inverse Bidi" algorithm. + * This mode is similar to mode <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code> + * but is closer to the regular Bidi algorithm. + * <br> + * For example, an LTR paragraph with the content "FED 123 456 CBA" (where + * upper case represents RTL characters) will be transformed to + * "ABC 456 123 DEF", as opposed to "DEF 123 456 ABC" + * with mode <code>UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>.<br> + * When used in conjunction with option + * <code>#UBIDI_OPTION_INSERT_MARKS</code>, this mode generally + * adds Bidi marks to the output significantly more sparingly than mode + * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code> with option + * <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code> in calls to + * <code>ubidi_writeReordered</code>.</li> + * + * <li>When the reordering mode is set to + * <code>#UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code>, the Logical to Visual + * Bidi algorithm used in Windows XP is used as an approximation of an "inverse Bidi" algorithm. + * <br> + * For example, an LTR paragraph with the content "abc FED123" (where + * upper case represents RTL characters) will be transformed to "abc 123DEF."</li> + * </ul> + * + * <p>In all the reordering modes specifying an "inverse Bidi" algorithm + * (i.e. those with a name starting with <code>UBIDI_REORDER_INVERSE</code>), + * output runs should be retrieved using + * <code>ubidi_getVisualRun()</code>, and the output text with + * <code>ubidi_writeReordered()</code>. The caller should keep in mind that in + * "inverse Bidi" modes the input is actually visually ordered text and + * reordered output returned by <code>ubidi_getVisualRun()</code> or + * <code>ubidi_writeReordered()</code> are actually runs or character string + * of logically ordered output.<br> + * For all the "inverse Bidi" modes, the source text should not contain + * Bidi control characters other than LRM or RLM.</p> + * + * <p>Note that option <code>#UBIDI_OUTPUT_REVERSE</code> of + * <code>ubidi_writeReordered</code> has no useful meaning and should not be + * used in conjunction with any value of the reordering mode specifying + * "inverse Bidi" or with value <code>UBIDI_REORDER_RUNS_ONLY</code>. + * + * @param pBiDi is a <code>UBiDi</code> object. + * @param reorderingMode specifies the required variant of the Bidi algorithm. + * + * @see UBiDiReorderingMode + * @see ubidi_setInverse + * @see ubidi_setPara + * @see ubidi_writeReordered + * @stable ICU 3.6 + */ +U_CAPI void U_EXPORT2 +ubidi_setReorderingMode(UBiDi *pBiDi, UBiDiReorderingMode reorderingMode); + +/** + * What is the requested reordering mode for a given Bidi object? + * + * @param pBiDi is a <code>UBiDi</code> object. + * @return the current reordering mode of the Bidi object + * @see ubidi_setReorderingMode + * @stable ICU 3.6 + */ +U_CAPI UBiDiReorderingMode U_EXPORT2 +ubidi_getReorderingMode(UBiDi *pBiDi); + +/** + * <code>UBiDiReorderingOption</code> values indicate which options are + * specified to affect the Bidi algorithm. + * + * @see ubidi_setReorderingOptions + * @stable ICU 3.6 + */ +typedef enum UBiDiReorderingOption { + /** + * option value for <code>ubidi_setReorderingOptions</code>: + * disable all the options which can be set with this function + * @see ubidi_setReorderingOptions + * @stable ICU 3.6 + */ + UBIDI_OPTION_DEFAULT = 0, + + /** + * option bit for <code>ubidi_setReorderingOptions</code>: + * insert Bidi marks (LRM or RLM) when needed to ensure correct result of + * a reordering to a Logical order + * + * <p>This option must be set or reset before calling + * <code>ubidi_setPara</code>.</p> + * + * <p>This option is significant only with reordering modes which generate + * a result with Logical order, specifically:</p> + * <ul> + * <li><code>#UBIDI_REORDER_RUNS_ONLY</code></li> + * <li><code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code></li> + * <li><code>#UBIDI_REORDER_INVERSE_LIKE_DIRECT</code></li> + * <li><code>#UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code></li> + * </ul> + * + * <p>If this option is set in conjunction with reordering mode + * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code> or with calling + * <code>ubidi_setInverse(true)</code>, it implies + * option <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code> + * in calls to function <code>ubidi_writeReordered()</code>.</p> + * + * <p>For other reordering modes, a minimum number of LRM or RLM characters + * will be added to the source text after reordering it so as to ensure + * round trip, i.e. when applying the inverse reordering mode on the + * resulting logical text with removal of Bidi marks + * (option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> set before calling + * <code>ubidi_setPara()</code> or option <code>#UBIDI_REMOVE_BIDI_CONTROLS</code> + * in <code>ubidi_writeReordered</code>), the result will be identical to the + * source text in the first transformation. + * + * <p>This option will be ignored if specified together with option + * <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>. It inhibits option + * <code>UBIDI_REMOVE_BIDI_CONTROLS</code> in calls to function + * <code>ubidi_writeReordered()</code> and it implies option + * <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code> in calls to function + * <code>ubidi_writeReordered()</code> if the reordering mode is + * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>.</p> + * + * @see ubidi_setReorderingMode + * @see ubidi_setReorderingOptions + * @stable ICU 3.6 + */ + UBIDI_OPTION_INSERT_MARKS = 1, + + /** + * option bit for <code>ubidi_setReorderingOptions</code>: + * remove Bidi control characters + * + * <p>This option must be set or reset before calling + * <code>ubidi_setPara</code>.</p> + * + * <p>This option nullifies option <code>#UBIDI_OPTION_INSERT_MARKS</code>. + * It inhibits option <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code> in calls + * to function <code>ubidi_writeReordered()</code> and it implies option + * <code>#UBIDI_REMOVE_BIDI_CONTROLS</code> in calls to that function.</p> + * + * @see ubidi_setReorderingMode + * @see ubidi_setReorderingOptions + * @stable ICU 3.6 + */ + UBIDI_OPTION_REMOVE_CONTROLS = 2, + + /** + * option bit for <code>ubidi_setReorderingOptions</code>: + * process the output as part of a stream to be continued + * + * <p>This option must be set or reset before calling + * <code>ubidi_setPara</code>.</p> + * + * <p>This option specifies that the caller is interested in processing large + * text object in parts. + * The results of the successive calls are expected to be concatenated by the + * caller. Only the call for the last part will have this option bit off.</p> + * + * <p>When this option bit is on, <code>ubidi_setPara()</code> may process + * less than the full source text in order to truncate the text at a meaningful + * boundary. The caller should call <code>ubidi_getProcessedLength()</code> + * immediately after calling <code>ubidi_setPara()</code> in order to + * determine how much of the source text has been processed. + * Source text beyond that length should be resubmitted in following calls to + * <code>ubidi_setPara</code>. The processed length may be less than + * the length of the source text if a character preceding the last character of + * the source text constitutes a reasonable boundary (like a block separator) + * for text to be continued.<br> + * If the last character of the source text constitutes a reasonable + * boundary, the whole text will be processed at once.<br> + * If nowhere in the source text there exists + * such a reasonable boundary, the processed length will be zero.<br> + * The caller should check for such an occurrence and do one of the following: + * <ul><li>submit a larger amount of text with a better chance to include + * a reasonable boundary.</li> + * <li>resubmit the same text after turning off option + * <code>UBIDI_OPTION_STREAMING</code>.</li></ul> + * In all cases, this option should be turned off before processing the last + * part of the text.</p> + * + * <p>When the <code>UBIDI_OPTION_STREAMING</code> option is used, + * it is recommended to call <code>ubidi_orderParagraphsLTR()</code> with + * argument <code>orderParagraphsLTR</code> set to <code>true</code> before + * calling <code>ubidi_setPara</code> so that later paragraphs may be + * concatenated to previous paragraphs on the right.</p> + * + * @see ubidi_setReorderingMode + * @see ubidi_setReorderingOptions + * @see ubidi_getProcessedLength + * @see ubidi_orderParagraphsLTR + * @stable ICU 3.6 + */ + UBIDI_OPTION_STREAMING = 4 +} UBiDiReorderingOption; + +/** + * Specify which of the reordering options + * should be applied during Bidi transformations. + * + * @param pBiDi is a <code>UBiDi</code> object. + * @param reorderingOptions is a combination of zero or more of the following + * options: + * <code>#UBIDI_OPTION_DEFAULT</code>, <code>#UBIDI_OPTION_INSERT_MARKS</code>, + * <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>, <code>#UBIDI_OPTION_STREAMING</code>. + * + * @see ubidi_getReorderingOptions + * @stable ICU 3.6 + */ +U_CAPI void U_EXPORT2 +ubidi_setReorderingOptions(UBiDi *pBiDi, uint32_t reorderingOptions); + +/** + * What are the reordering options applied to a given Bidi object? + * + * @param pBiDi is a <code>UBiDi</code> object. + * @return the current reordering options of the Bidi object + * @see ubidi_setReorderingOptions + * @stable ICU 3.6 + */ +U_CAPI uint32_t U_EXPORT2 +ubidi_getReorderingOptions(UBiDi *pBiDi); + +/** + * Set the context before a call to ubidi_setPara().<p> + * + * ubidi_setPara() computes the left-right directionality for a given piece + * of text which is supplied as one of its arguments. Sometimes this piece + * of text (the "main text") should be considered in context, because text + * appearing before ("prologue") and/or after ("epilogue") the main text + * may affect the result of this computation.<p> + * + * This function specifies the prologue and/or the epilogue for the next + * call to ubidi_setPara(). The characters specified as prologue and + * epilogue should not be modified by the calling program until the call + * to ubidi_setPara() has returned. If successive calls to ubidi_setPara() + * all need specification of a context, ubidi_setContext() must be called + * before each call to ubidi_setPara(). In other words, a context is not + * "remembered" after the following successful call to ubidi_setPara().<p> + * + * If a call to ubidi_setPara() specifies UBIDI_DEFAULT_LTR or + * UBIDI_DEFAULT_RTL as paraLevel and is preceded by a call to + * ubidi_setContext() which specifies a prologue, the paragraph level will + * be computed taking in consideration the text in the prologue.<p> + * + * When ubidi_setPara() is called without a previous call to + * ubidi_setContext, the main text is handled as if preceded and followed + * by strong directional characters at the current paragraph level. + * Calling ubidi_setContext() with specification of a prologue will change + * this behavior by handling the main text as if preceded by the last + * strong character appearing in the prologue, if any. + * Calling ubidi_setContext() with specification of an epilogue will change + * the behavior of ubidi_setPara() by handling the main text as if followed + * by the first strong character or digit appearing in the epilogue, if any.<p> + * + * Note 1: if <code>ubidi_setContext</code> is called repeatedly without + * calling <code>ubidi_setPara</code>, the earlier calls have no effect, + * only the last call will be remembered for the next call to + * <code>ubidi_setPara</code>.<p> + * + * Note 2: calling <code>ubidi_setContext(pBiDi, NULL, 0, NULL, 0, &errorCode)</code> + * cancels any previous setting of non-empty prologue or epilogue. + * The next call to <code>ubidi_setPara()</code> will process no + * prologue or epilogue.<p> + * + * Note 3: users must be aware that even after setting the context + * before a call to ubidi_setPara() to perform e.g. a logical to visual + * transformation, the resulting string may not be identical to what it + * would have been if all the text, including prologue and epilogue, had + * been processed together.<br> + * Example (upper case letters represent RTL characters):<br> + * prologue = "<code>abc DE</code>"<br> + * epilogue = none<br> + * main text = "<code>FGH xyz</code>"<br> + * paraLevel = UBIDI_LTR<br> + * display without prologue = "<code>HGF xyz</code>" + * ("HGF" is adjacent to "xyz")<br> + * display with prologue = "<code>abc HGFED xyz</code>" + * ("HGF" is not adjacent to "xyz")<br> + * + * @param pBiDi is a paragraph <code>UBiDi</code> object. + * + * @param prologue is a pointer to the text which precedes the text that + * will be specified in a coming call to ubidi_setPara(). + * If there is no prologue to consider, then <code>proLength</code> + * must be zero and this pointer can be NULL. + * + * @param proLength is the length of the prologue; if <code>proLength==-1</code> + * then the prologue must be zero-terminated. + * Otherwise proLength must be >= 0. If <code>proLength==0</code>, it means + * that there is no prologue to consider. + * + * @param epilogue is a pointer to the text which follows the text that + * will be specified in a coming call to ubidi_setPara(). + * If there is no epilogue to consider, then <code>epiLength</code> + * must be zero and this pointer can be NULL. + * + * @param epiLength is the length of the epilogue; if <code>epiLength==-1</code> + * then the epilogue must be zero-terminated. + * Otherwise epiLength must be >= 0. If <code>epiLength==0</code>, it means + * that there is no epilogue to consider. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @see ubidi_setPara + * @stable ICU 4.8 + */ +U_CAPI void U_EXPORT2 +ubidi_setContext(UBiDi *pBiDi, + const UChar *prologue, int32_t proLength, + const UChar *epilogue, int32_t epiLength, + UErrorCode *pErrorCode); + +/** + * Perform the Unicode Bidi algorithm. It is defined in the + * <a href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Annex #9</a>, + * version 13, + * also described in The Unicode Standard, Version 4.0 .<p> + * + * This function takes a piece of plain text containing one or more paragraphs, + * with or without externally specified embedding levels from <i>styled</i> + * text and computes the left-right-directionality of each character.<p> + * + * If the entire text is all of the same directionality, then + * the function may not perform all the steps described by the algorithm, + * i.e., some levels may not be the same as if all steps were performed. + * This is not relevant for unidirectional text.<br> + * For example, in pure LTR text with numbers the numbers would get + * a resolved level of 2 higher than the surrounding text according to + * the algorithm. This implementation may set all resolved levels to + * the same value in such a case.<p> + * + * The text can be composed of multiple paragraphs. Occurrence of a block + * separator in the text terminates a paragraph, and whatever comes next starts + * a new paragraph. The exception to this rule is when a Carriage Return (CR) + * is followed by a Line Feed (LF). Both CR and LF are block separators, but + * in that case, the pair of characters is considered as terminating the + * preceding paragraph, and a new paragraph will be started by a character + * coming after the LF. + * + * @param pBiDi A <code>UBiDi</code> object allocated with <code>ubidi_open()</code> + * which will be set to contain the reordering information, + * especially the resolved levels for all the characters in <code>text</code>. + * + * @param text is a pointer to the text that the Bidi algorithm will be performed on. + * This pointer is stored in the UBiDi object and can be retrieved + * with <code>ubidi_getText()</code>.<br> + * <strong>Note:</strong> the text must be (at least) <code>length</code> long. + * + * @param length is the length of the text; if <code>length==-1</code> then + * the text must be zero-terminated. + * + * @param paraLevel specifies the default level for the text; + * it is typically 0 (LTR) or 1 (RTL). + * If the function shall determine the paragraph level from the text, + * then <code>paraLevel</code> can be set to + * either <code>#UBIDI_DEFAULT_LTR</code> + * or <code>#UBIDI_DEFAULT_RTL</code>; if the text contains multiple + * paragraphs, the paragraph level shall be determined separately for + * each paragraph; if a paragraph does not include any strongly typed + * character, then the desired default is used (0 for LTR or 1 for RTL). + * Any other value between 0 and <code>#UBIDI_MAX_EXPLICIT_LEVEL</code> + * is also valid, with odd levels indicating RTL. + * + * @param embeddingLevels (in) may be used to preset the embedding and override levels, + * ignoring characters like LRE and PDF in the text. + * A level overrides the directional property of its corresponding + * (same index) character if the level has the + * <code>#UBIDI_LEVEL_OVERRIDE</code> bit set.<br><br> + * Aside from that bit, it must be + * <code>paraLevel<=embeddingLevels[]<=UBIDI_MAX_EXPLICIT_LEVEL</code>, + * except that level 0 is always allowed. + * Level 0 for a paragraph separator prevents reordering of paragraphs; + * this only works reliably if <code>#UBIDI_LEVEL_OVERRIDE</code> + * is also set for paragraph separators. + * Level 0 for other characters is treated as a wildcard + * and is lifted up to the resolved level of the surrounding paragraph.<br><br> + * <strong>Caution: </strong>A copy of this pointer, not of the levels, + * will be stored in the <code>UBiDi</code> object; + * the <code>embeddingLevels</code> array must not be + * deallocated before the <code>UBiDi</code> structure is destroyed or reused, + * and the <code>embeddingLevels</code> + * should not be modified to avoid unexpected results on subsequent Bidi operations. + * However, the <code>ubidi_setPara()</code> and + * <code>ubidi_setLine()</code> functions may modify some or all of the levels.<br><br> + * After the <code>UBiDi</code> object is reused or destroyed, the caller + * must take care of the deallocation of the <code>embeddingLevels</code> array.<br><br> + * <strong>Note:</strong> the <code>embeddingLevels</code> array must be + * at least <code>length</code> long. + * This pointer can be <code>NULL</code> if this + * value is not necessary. + * + * @param pErrorCode must be a valid pointer to an error code value. + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_setPara(UBiDi *pBiDi, const UChar *text, int32_t length, + UBiDiLevel paraLevel, UBiDiLevel *embeddingLevels, + UErrorCode *pErrorCode); + +/** + * <code>ubidi_setLine()</code> sets a <code>UBiDi</code> to + * contain the reordering information, especially the resolved levels, + * for all the characters in a line of text. This line of text is + * specified by referring to a <code>UBiDi</code> object representing + * this information for a piece of text containing one or more paragraphs, + * and by specifying a range of indexes in this text.<p> + * In the new line object, the indexes will range from 0 to <code>limit-start-1</code>.<p> + * + * This is used after calling <code>ubidi_setPara()</code> + * for a piece of text, and after line-breaking on that text. + * It is not necessary if each paragraph is treated as a single line.<p> + * + * After line-breaking, rules (L1) and (L2) for the treatment of + * trailing WS and for reordering are performed on + * a <code>UBiDi</code> object that represents a line.<p> + * + * <strong>Important: </strong><code>pLineBiDi</code> shares data with + * <code>pParaBiDi</code>. + * You must destroy or reuse <code>pLineBiDi</code> before <code>pParaBiDi</code>. + * In other words, you must destroy or reuse the <code>UBiDi</code> object for a line + * before the object for its parent paragraph.<p> + * + * The text pointer that was stored in <code>pParaBiDi</code> is also copied, + * and <code>start</code> is added to it so that it points to the beginning of the + * line for this object. + * + * @param pParaBiDi is the parent paragraph object. It must have been set + * by a successful call to ubidi_setPara. + * + * @param start is the line's first index into the text. + * + * @param limit is just behind the line's last index into the text + * (its last index +1).<br> + * It must be <code>0<=start<limit<=</code>containing paragraph limit. + * If the specified line crosses a paragraph boundary, the function + * will terminate with error code U_ILLEGAL_ARGUMENT_ERROR. + * + * @param pLineBiDi is the object that will now represent a line of the text. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @see ubidi_setPara + * @see ubidi_getProcessedLength + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_setLine(const UBiDi *pParaBiDi, + int32_t start, int32_t limit, + UBiDi *pLineBiDi, + UErrorCode *pErrorCode); + +/** + * Get the directionality of the text. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @return a value of <code>UBIDI_LTR</code>, <code>UBIDI_RTL</code> + * or <code>UBIDI_MIXED</code> + * that indicates if the entire text + * represented by this object is unidirectional, + * and which direction, or if it is mixed-directional. + * Note - The value <code>UBIDI_NEUTRAL</code> is never returned from this method. + * + * @see UBiDiDirection + * @stable ICU 2.0 + */ +U_CAPI UBiDiDirection U_EXPORT2 +ubidi_getDirection(const UBiDi *pBiDi); + +/** + * Gets the base direction of the text provided according + * to the Unicode Bidirectional Algorithm. The base direction + * is derived from the first character in the string with bidirectional + * character type L, R, or AL. If the first such character has type L, + * <code>UBIDI_LTR</code> is returned. If the first such character has + * type R or AL, <code>UBIDI_RTL</code> is returned. If the string does + * not contain any character of these types, then + * <code>UBIDI_NEUTRAL</code> is returned. + * + * This is a lightweight function for use when only the base direction + * is needed and no further bidi processing of the text is needed. + * + * @param text is a pointer to the text whose base + * direction is needed. + * Note: the text must be (at least) @c length long. + * + * @param length is the length of the text; + * if <code>length==-1</code> then the text + * must be zero-terminated. + * + * @return <code>UBIDI_LTR</code>, <code>UBIDI_RTL</code>, + * <code>UBIDI_NEUTRAL</code> + * + * @see UBiDiDirection + * @stable ICU 4.6 + */ +U_CAPI UBiDiDirection U_EXPORT2 +ubidi_getBaseDirection(const UChar *text, int32_t length ); + +/** + * Get the pointer to the text. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @return The pointer to the text that the UBiDi object was created for. + * + * @see ubidi_setPara + * @see ubidi_setLine + * @stable ICU 2.0 + */ +U_CAPI const UChar * U_EXPORT2 +ubidi_getText(const UBiDi *pBiDi); + +/** + * Get the length of the text. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @return The length of the text that the UBiDi object was created for. + * @stable ICU 2.0 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_getLength(const UBiDi *pBiDi); + +/** + * Get the paragraph level of the text. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @return The paragraph level. If there are multiple paragraphs, their + * level may vary if the required paraLevel is UBIDI_DEFAULT_LTR or + * UBIDI_DEFAULT_RTL. In that case, the level of the first paragraph + * is returned. + * + * @see UBiDiLevel + * @see ubidi_getParagraph + * @see ubidi_getParagraphByIndex + * @stable ICU 2.0 + */ +U_CAPI UBiDiLevel U_EXPORT2 +ubidi_getParaLevel(const UBiDi *pBiDi); + +/** + * Get the number of paragraphs. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @return The number of paragraphs. + * @stable ICU 3.4 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_countParagraphs(UBiDi *pBiDi); + +/** + * Get a paragraph, given a position within the text. + * This function returns information about a paragraph.<br> + * Note: if the paragraph index is known, it is more efficient to + * retrieve the paragraph information using ubidi_getParagraphByIndex().<p> + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @param charIndex is the index of a character within the text, in the + * range <code>[0..ubidi_getProcessedLength(pBiDi)-1]</code>. + * + * @param pParaStart will receive the index of the first character of the + * paragraph in the text. + * This pointer can be <code>NULL</code> if this + * value is not necessary. + * + * @param pParaLimit will receive the limit of the paragraph. + * The l-value that you point to here may be the + * same expression (variable) as the one for + * <code>charIndex</code>. + * This pointer can be <code>NULL</code> if this + * value is not necessary. + * + * @param pParaLevel will receive the level of the paragraph. + * This pointer can be <code>NULL</code> if this + * value is not necessary. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @return The index of the paragraph containing the specified position. + * + * @see ubidi_getProcessedLength + * @stable ICU 3.4 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_getParagraph(const UBiDi *pBiDi, int32_t charIndex, int32_t *pParaStart, + int32_t *pParaLimit, UBiDiLevel *pParaLevel, + UErrorCode *pErrorCode); + +/** + * Get a paragraph, given the index of this paragraph. + * + * This function returns information about a paragraph.<p> + * + * @param pBiDi is the paragraph <code>UBiDi</code> object. + * + * @param paraIndex is the number of the paragraph, in the + * range <code>[0..ubidi_countParagraphs(pBiDi)-1]</code>. + * + * @param pParaStart will receive the index of the first character of the + * paragraph in the text. + * This pointer can be <code>NULL</code> if this + * value is not necessary. + * + * @param pParaLimit will receive the limit of the paragraph. + * This pointer can be <code>NULL</code> if this + * value is not necessary. + * + * @param pParaLevel will receive the level of the paragraph. + * This pointer can be <code>NULL</code> if this + * value is not necessary. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @stable ICU 3.4 + */ +U_CAPI void U_EXPORT2 +ubidi_getParagraphByIndex(const UBiDi *pBiDi, int32_t paraIndex, + int32_t *pParaStart, int32_t *pParaLimit, + UBiDiLevel *pParaLevel, UErrorCode *pErrorCode); + +/** + * Get the level for one character. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @param charIndex the index of a character. It must be in the range + * [0..ubidi_getProcessedLength(pBiDi)]. + * + * @return The level for the character at charIndex (0 if charIndex is not + * in the valid range). + * + * @see UBiDiLevel + * @see ubidi_getProcessedLength + * @stable ICU 2.0 + */ +U_CAPI UBiDiLevel U_EXPORT2 +ubidi_getLevelAt(const UBiDi *pBiDi, int32_t charIndex); + +/** + * Get an array of levels for each character.<p> + * + * Note that this function may allocate memory under some + * circumstances, unlike <code>ubidi_getLevelAt()</code>. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object, whose + * text length must be strictly positive. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @return The levels array for the text, + * or <code>NULL</code> if an error occurs. + * + * @see UBiDiLevel + * @see ubidi_getProcessedLength + * @stable ICU 2.0 + */ +U_CAPI const UBiDiLevel * U_EXPORT2 +ubidi_getLevels(UBiDi *pBiDi, UErrorCode *pErrorCode); + +/** + * Get a logical run. + * This function returns information about a run and is used + * to retrieve runs in logical order.<p> + * This is especially useful for line-breaking on a paragraph. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @param logicalPosition is a logical position within the source text. + * + * @param pLogicalLimit will receive the limit of the corresponding run. + * The l-value that you point to here may be the + * same expression (variable) as the one for + * <code>logicalPosition</code>. + * This pointer can be <code>NULL</code> if this + * value is not necessary. + * + * @param pLevel will receive the level of the corresponding run. + * This pointer can be <code>NULL</code> if this + * value is not necessary. + * + * @see ubidi_getProcessedLength + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_getLogicalRun(const UBiDi *pBiDi, int32_t logicalPosition, + int32_t *pLogicalLimit, UBiDiLevel *pLevel); + +/** + * Get the number of runs. + * This function may invoke the actual reordering on the + * <code>UBiDi</code> object, after <code>ubidi_setPara()</code> + * may have resolved only the levels of the text. Therefore, + * <code>ubidi_countRuns()</code> may have to allocate memory, + * and may fail doing so. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @return The number of runs. + * @stable ICU 2.0 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_countRuns(UBiDi *pBiDi, UErrorCode *pErrorCode); + +/** + * Get one run's logical start, length, and directionality, + * which can be 0 for LTR or 1 for RTL. + * In an RTL run, the character at the logical start is + * visually on the right of the displayed run. + * The length is the number of characters in the run.<p> + * <code>ubidi_countRuns()</code> should be called + * before the runs are retrieved. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @param runIndex is the number of the run in visual order, in the + * range <code>[0..ubidi_countRuns(pBiDi)-1]</code>. + * + * @param pLogicalStart is the first logical character index in the text. + * The pointer may be <code>NULL</code> if this index is not needed. + * + * @param pLength is the number of characters (at least one) in the run. + * The pointer may be <code>NULL</code> if this is not needed. + * + * @return the directionality of the run, + * <code>UBIDI_LTR==0</code> or <code>UBIDI_RTL==1</code>, + * never <code>UBIDI_MIXED</code>, + * never <code>UBIDI_NEUTRAL</code>. + * + * @see ubidi_countRuns + * + * Example: + * <pre> + * \code + * int32_t i, count=ubidi_countRuns(pBiDi), + * logicalStart, visualIndex=0, length; + * for(i=0; i<count; ++i) { + * if(UBIDI_LTR==ubidi_getVisualRun(pBiDi, i, &logicalStart, &length)) { + * do { // LTR + * show_char(text[logicalStart++], visualIndex++); + * } while(--length>0); + * } else { + * logicalStart+=length; // logicalLimit + * do { // RTL + * show_char(text[--logicalStart], visualIndex++); + * } while(--length>0); + * } + * } + *\endcode + * </pre> + * + * Note that in right-to-left runs, code like this places + * second surrogates before first ones (which is generally a bad idea) + * and combining characters before base characters. + * <p> + * Use of <code>ubidi_writeReordered()</code>, optionally with the + * <code>#UBIDI_KEEP_BASE_COMBINING</code> option, can be considered in order + * to avoid these issues. + * @stable ICU 2.0 + */ +U_CAPI UBiDiDirection U_EXPORT2 +ubidi_getVisualRun(UBiDi *pBiDi, int32_t runIndex, + int32_t *pLogicalStart, int32_t *pLength); + +/** + * Get the visual position from a logical text position. + * If such a mapping is used many times on the same + * <code>UBiDi</code> object, then calling + * <code>ubidi_getLogicalMap()</code> is more efficient.<p> + * + * The value returned may be <code>#UBIDI_MAP_NOWHERE</code> if there is no + * visual position because the corresponding text character is a Bidi control + * removed from output by the option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>. + * <p> + * When the visual output is altered by using options of + * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>, + * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>, + * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the visual position returned may not + * be correct. It is advised to use, when possible, reordering options + * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_CONTROLS</code>. + * <p> + * Note that in right-to-left runs, this mapping places + * second surrogates before first ones (which is generally a bad idea) + * and combining characters before base characters. + * Use of <code>ubidi_writeReordered()</code>, optionally with the + * <code>#UBIDI_KEEP_BASE_COMBINING</code> option can be considered instead + * of using the mapping, in order to avoid these issues. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @param logicalIndex is the index of a character in the text. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @return The visual position of this character. + * + * @see ubidi_getLogicalMap + * @see ubidi_getLogicalIndex + * @see ubidi_getProcessedLength + * @stable ICU 2.0 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_getVisualIndex(UBiDi *pBiDi, int32_t logicalIndex, UErrorCode *pErrorCode); + +/** + * Get the logical text position from a visual position. + * If such a mapping is used many times on the same + * <code>UBiDi</code> object, then calling + * <code>ubidi_getVisualMap()</code> is more efficient.<p> + * + * The value returned may be <code>#UBIDI_MAP_NOWHERE</code> if there is no + * logical position because the corresponding text character is a Bidi mark + * inserted in the output by option <code>#UBIDI_OPTION_INSERT_MARKS</code>. + * <p> + * This is the inverse function to <code>ubidi_getVisualIndex()</code>. + * <p> + * When the visual output is altered by using options of + * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>, + * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>, + * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the logical position returned may not + * be correct. It is advised to use, when possible, reordering options + * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_CONTROLS</code>. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @param visualIndex is the visual position of a character. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @return The index of this character in the text. + * + * @see ubidi_getVisualMap + * @see ubidi_getVisualIndex + * @see ubidi_getResultLength + * @stable ICU 2.0 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_getLogicalIndex(UBiDi *pBiDi, int32_t visualIndex, UErrorCode *pErrorCode); + +/** + * Get a logical-to-visual index map (array) for the characters in the UBiDi + * (paragraph or line) object. + * <p> + * Some values in the map may be <code>#UBIDI_MAP_NOWHERE</code> if the + * corresponding text characters are Bidi controls removed from the visual + * output by the option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>. + * <p> + * When the visual output is altered by using options of + * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>, + * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>, + * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the visual positions returned may not + * be correct. It is advised to use, when possible, reordering options + * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_CONTROLS</code>. + * <p> + * Note that in right-to-left runs, this mapping places + * second surrogates before first ones (which is generally a bad idea) + * and combining characters before base characters. + * Use of <code>ubidi_writeReordered()</code>, optionally with the + * <code>#UBIDI_KEEP_BASE_COMBINING</code> option can be considered instead + * of using the mapping, in order to avoid these issues. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @param indexMap is a pointer to an array of <code>ubidi_getProcessedLength()</code> + * indexes which will reflect the reordering of the characters. + * If option <code>#UBIDI_OPTION_INSERT_MARKS</code> is set, the number + * of elements allocated in <code>indexMap</code> must be no less than + * <code>ubidi_getResultLength()</code>. + * The array does not need to be initialized.<br><br> + * The index map will result in <code>indexMap[logicalIndex]==visualIndex</code>. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @see ubidi_getVisualMap + * @see ubidi_getVisualIndex + * @see ubidi_getProcessedLength + * @see ubidi_getResultLength + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_getLogicalMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode); + +/** + * Get a visual-to-logical index map (array) for the characters in the UBiDi + * (paragraph or line) object. + * <p> + * Some values in the map may be <code>#UBIDI_MAP_NOWHERE</code> if the + * corresponding text characters are Bidi marks inserted in the visual output + * by the option <code>#UBIDI_OPTION_INSERT_MARKS</code>. + * <p> + * When the visual output is altered by using options of + * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>, + * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>, + * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the logical positions returned may not + * be correct. It is advised to use, when possible, reordering options + * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_CONTROLS</code>. + * + * @param pBiDi is the paragraph or line <code>UBiDi</code> object. + * + * @param indexMap is a pointer to an array of <code>ubidi_getResultLength()</code> + * indexes which will reflect the reordering of the characters. + * If option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> is set, the number + * of elements allocated in <code>indexMap</code> must be no less than + * <code>ubidi_getProcessedLength()</code>. + * The array does not need to be initialized.<br><br> + * The index map will result in <code>indexMap[visualIndex]==logicalIndex</code>. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @see ubidi_getLogicalMap + * @see ubidi_getLogicalIndex + * @see ubidi_getProcessedLength + * @see ubidi_getResultLength + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_getVisualMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode); + +/** + * This is a convenience function that does not use a UBiDi object. + * It is intended to be used for when an application has determined the levels + * of objects (character sequences) and just needs to have them reordered (L2). + * This is equivalent to using <code>ubidi_getLogicalMap()</code> on a + * <code>UBiDi</code> object. + * + * @param levels is an array with <code>length</code> levels that have been determined by + * the application. + * + * @param length is the number of levels in the array, or, semantically, + * the number of objects to be reordered. + * It must be <code>length>0</code>. + * + * @param indexMap is a pointer to an array of <code>length</code> + * indexes which will reflect the reordering of the characters. + * The array does not need to be initialized.<p> + * The index map will result in <code>indexMap[logicalIndex]==visualIndex</code>. + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_reorderLogical(const UBiDiLevel *levels, int32_t length, int32_t *indexMap); + +/** + * This is a convenience function that does not use a UBiDi object. + * It is intended to be used for when an application has determined the levels + * of objects (character sequences) and just needs to have them reordered (L2). + * This is equivalent to using <code>ubidi_getVisualMap()</code> on a + * <code>UBiDi</code> object. + * + * @param levels is an array with <code>length</code> levels that have been determined by + * the application. + * + * @param length is the number of levels in the array, or, semantically, + * the number of objects to be reordered. + * It must be <code>length>0</code>. + * + * @param indexMap is a pointer to an array of <code>length</code> + * indexes which will reflect the reordering of the characters. + * The array does not need to be initialized.<p> + * The index map will result in <code>indexMap[visualIndex]==logicalIndex</code>. + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_reorderVisual(const UBiDiLevel *levels, int32_t length, int32_t *indexMap); + +/** + * Invert an index map. + * The index mapping of the first map is inverted and written to + * the second one. + * + * @param srcMap is an array with <code>length</code> elements + * which defines the original mapping from a source array containing + * <code>length</code> elements to a destination array. + * Some elements of the source array may have no mapping in the + * destination array. In that case, their value will be + * the special value <code>UBIDI_MAP_NOWHERE</code>. + * All elements must be >=0 or equal to <code>UBIDI_MAP_NOWHERE</code>. + * Some elements may have a value >= <code>length</code>, if the + * destination array has more elements than the source array. + * There must be no duplicate indexes (two or more elements with the + * same value except <code>UBIDI_MAP_NOWHERE</code>). + * + * @param destMap is an array with a number of elements equal to 1 + the highest + * value in <code>srcMap</code>. + * <code>destMap</code> will be filled with the inverse mapping. + * If element with index i in <code>srcMap</code> has a value k different + * from <code>UBIDI_MAP_NOWHERE</code>, this means that element i of + * the source array maps to element k in the destination array. + * The inverse map will have value i in its k-th element. + * For all elements of the destination array which do not map to + * an element in the source array, the corresponding element in the + * inverse map will have a value equal to <code>UBIDI_MAP_NOWHERE</code>. + * + * @param length is the length of each array. + * @see UBIDI_MAP_NOWHERE + * @stable ICU 2.0 + */ +U_CAPI void U_EXPORT2 +ubidi_invertMap(const int32_t *srcMap, int32_t *destMap, int32_t length); + +/** option flags for ubidi_writeReordered() */ + +/** + * option bit for ubidi_writeReordered(): + * keep combining characters after their base characters in RTL runs + * + * @see ubidi_writeReordered + * @stable ICU 2.0 + */ +#define UBIDI_KEEP_BASE_COMBINING 1 + +/** + * option bit for ubidi_writeReordered(): + * replace characters with the "mirrored" property in RTL runs + * by their mirror-image mappings + * + * @see ubidi_writeReordered + * @stable ICU 2.0 + */ +#define UBIDI_DO_MIRRORING 2 + +/** + * option bit for ubidi_writeReordered(): + * surround the run with LRMs if necessary; + * this is part of the approximate "inverse Bidi" algorithm + * + * <p>This option does not imply corresponding adjustment of the index + * mappings.</p> + * + * @see ubidi_setInverse + * @see ubidi_writeReordered + * @stable ICU 2.0 + */ +#define UBIDI_INSERT_LRM_FOR_NUMERIC 4 + +/** + * option bit for ubidi_writeReordered(): + * remove Bidi control characters + * (this does not affect #UBIDI_INSERT_LRM_FOR_NUMERIC) + * + * <p>This option does not imply corresponding adjustment of the index + * mappings.</p> + * + * @see ubidi_writeReordered + * @stable ICU 2.0 + */ +#define UBIDI_REMOVE_BIDI_CONTROLS 8 + +/** + * option bit for ubidi_writeReordered(): + * write the output in reverse order + * + * <p>This has the same effect as calling <code>ubidi_writeReordered()</code> + * first without this option, and then calling + * <code>ubidi_writeReverse()</code> without mirroring. + * Doing this in the same step is faster and avoids a temporary buffer. + * An example for using this option is output to a character terminal that + * is designed for RTL scripts and stores text in reverse order.</p> + * + * @see ubidi_writeReordered + * @stable ICU 2.0 + */ +#define UBIDI_OUTPUT_REVERSE 16 + +/** + * Get the length of the source text processed by the last call to + * <code>ubidi_setPara()</code>. This length may be different from the length + * of the source text if option <code>#UBIDI_OPTION_STREAMING</code> + * has been set. + * <br> + * Note that whenever the length of the text affects the execution or the + * result of a function, it is the processed length which must be considered, + * except for <code>ubidi_setPara</code> (which receives unprocessed source + * text) and <code>ubidi_getLength</code> (which returns the original length + * of the source text).<br> + * In particular, the processed length is the one to consider in the following + * cases: + * <ul> + * <li>maximum value of the <code>limit</code> argument of + * <code>ubidi_setLine</code></li> + * <li>maximum value of the <code>charIndex</code> argument of + * <code>ubidi_getParagraph</code></li> + * <li>maximum value of the <code>charIndex</code> argument of + * <code>ubidi_getLevelAt</code></li> + * <li>number of elements in the array returned by <code>ubidi_getLevels</code></li> + * <li>maximum value of the <code>logicalStart</code> argument of + * <code>ubidi_getLogicalRun</code></li> + * <li>maximum value of the <code>logicalIndex</code> argument of + * <code>ubidi_getVisualIndex</code></li> + * <li>number of elements filled in the <code>*indexMap</code> argument of + * <code>ubidi_getLogicalMap</code></li> + * <li>length of text processed by <code>ubidi_writeReordered</code></li> + * </ul> + * + * @param pBiDi is the paragraph <code>UBiDi</code> object. + * + * @return The length of the part of the source text processed by + * the last call to <code>ubidi_setPara</code>. + * @see ubidi_setPara + * @see UBIDI_OPTION_STREAMING + * @stable ICU 3.6 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_getProcessedLength(const UBiDi *pBiDi); + +/** + * Get the length of the reordered text resulting from the last call to + * <code>ubidi_setPara()</code>. This length may be different from the length + * of the source text if option <code>#UBIDI_OPTION_INSERT_MARKS</code> + * or option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> has been set. + * <br> + * This resulting length is the one to consider in the following cases: + * <ul> + * <li>maximum value of the <code>visualIndex</code> argument of + * <code>ubidi_getLogicalIndex</code></li> + * <li>number of elements of the <code>*indexMap</code> argument of + * <code>ubidi_getVisualMap</code></li> + * </ul> + * Note that this length stays identical to the source text length if + * Bidi marks are inserted or removed using option bits of + * <code>ubidi_writeReordered</code>, or if option + * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code> has been set. + * + * @param pBiDi is the paragraph <code>UBiDi</code> object. + * + * @return The length of the reordered text resulting from + * the last call to <code>ubidi_setPara</code>. + * @see ubidi_setPara + * @see UBIDI_OPTION_INSERT_MARKS + * @see UBIDI_OPTION_REMOVE_CONTROLS + * @stable ICU 3.6 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_getResultLength(const UBiDi *pBiDi); + +U_CDECL_BEGIN + +#ifndef U_HIDE_DEPRECATED_API +/** + * Value returned by <code>UBiDiClassCallback</code> callbacks when + * there is no need to override the standard Bidi class for a given code point. + * + * This constant is deprecated; use u_getIntPropertyMaxValue(UCHAR_BIDI_CLASS)+1 instead. + * + * @see UBiDiClassCallback + * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420. + */ +#define U_BIDI_CLASS_DEFAULT U_CHAR_DIRECTION_COUNT +#endif // U_HIDE_DEPRECATED_API + +/** + * Callback type declaration for overriding default Bidi class values with + * custom ones. + * <p>Usually, the function pointer will be propagated to a <code>UBiDi</code> + * object by calling the <code>ubidi_setClassCallback()</code> function; + * then the callback will be invoked by the UBA implementation any time the + * class of a character is to be determined.</p> + * + * @param context is a pointer to the callback private data. + * + * @param c is the code point to get a Bidi class for. + * + * @return The directional property / Bidi class for the given code point + * <code>c</code> if the default class has been overridden, or + * <code>u_getIntPropertyMaxValue(UCHAR_BIDI_CLASS)+1</code> + * if the standard Bidi class value for <code>c</code> is to be used. + * @see ubidi_setClassCallback + * @see ubidi_getClassCallback + * @stable ICU 3.6 + */ +typedef UCharDirection U_CALLCONV +UBiDiClassCallback(const void *context, UChar32 c); + +U_CDECL_END + +/** + * Retrieve the Bidi class for a given code point. + * <p>If a <code>#UBiDiClassCallback</code> callback is defined and returns a + * value other than <code>u_getIntPropertyMaxValue(UCHAR_BIDI_CLASS)+1</code>, + * that value is used; otherwise the default class determination mechanism is invoked.</p> + * + * @param pBiDi is the paragraph <code>UBiDi</code> object. + * + * @param c is the code point whose Bidi class must be retrieved. + * + * @return The Bidi class for character <code>c</code> based + * on the given <code>pBiDi</code> instance. + * @see UBiDiClassCallback + * @stable ICU 3.6 + */ +U_CAPI UCharDirection U_EXPORT2 +ubidi_getCustomizedClass(UBiDi *pBiDi, UChar32 c); + +/** + * Set the callback function and callback data used by the UBA + * implementation for Bidi class determination. + * <p>This may be useful for assigning Bidi classes to PUA characters, or + * for special application needs. For instance, an application may want to + * handle all spaces like L or R characters (according to the base direction) + * when creating the visual ordering of logical lines which are part of a report + * organized in columns: there should not be interaction between adjacent + * cells.<p> + * + * @param pBiDi is the paragraph <code>UBiDi</code> object. + * + * @param newFn is the new callback function pointer. + * + * @param newContext is the new callback context pointer. This can be NULL. + * + * @param oldFn fillin: Returns the old callback function pointer. This can be + * NULL. + * + * @param oldContext fillin: Returns the old callback's context. This can be + * NULL. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @see ubidi_getClassCallback + * @stable ICU 3.6 + */ +U_CAPI void U_EXPORT2 +ubidi_setClassCallback(UBiDi *pBiDi, UBiDiClassCallback *newFn, + const void *newContext, UBiDiClassCallback **oldFn, + const void **oldContext, UErrorCode *pErrorCode); + +/** + * Get the current callback function used for Bidi class determination. + * + * @param pBiDi is the paragraph <code>UBiDi</code> object. + * + * @param fn fillin: Returns the callback function pointer. + * + * @param context fillin: Returns the callback's private context. + * + * @see ubidi_setClassCallback + * @stable ICU 3.6 + */ +U_CAPI void U_EXPORT2 +ubidi_getClassCallback(UBiDi *pBiDi, UBiDiClassCallback **fn, const void **context); + +/** + * Take a <code>UBiDi</code> object containing the reordering + * information for a piece of text (one or more paragraphs) set by + * <code>ubidi_setPara()</code> or for a line of text set by + * <code>ubidi_setLine()</code> and write a reordered string to the + * destination buffer. + * + * This function preserves the integrity of characters with multiple + * code units and (optionally) combining characters. + * Characters in RTL runs can be replaced by mirror-image characters + * in the destination buffer. Note that "real" mirroring has + * to be done in a rendering engine by glyph selection + * and that for many "mirrored" characters there are no + * Unicode characters as mirror-image equivalents. + * There are also options to insert or remove Bidi control + * characters; see the description of the <code>destSize</code> + * and <code>options</code> parameters and of the option bit flags. + * + * @param pBiDi A pointer to a <code>UBiDi</code> object that + * is set by <code>ubidi_setPara()</code> or + * <code>ubidi_setLine()</code> and contains the reordering + * information for the text that it was defined for, + * as well as a pointer to that text.<br><br> + * The text was aliased (only the pointer was stored + * without copying the contents) and must not have been modified + * since the <code>ubidi_setPara()</code> call. + * + * @param dest A pointer to where the reordered text is to be copied. + * The source text and <code>dest[destSize]</code> + * must not overlap. + * + * @param destSize The size of the <code>dest</code> buffer, + * in number of UChars. + * If the <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code> + * option is set, then the destination length could be + * as large as + * <code>ubidi_getLength(pBiDi)+2*ubidi_countRuns(pBiDi)</code>. + * If the <code>UBIDI_REMOVE_BIDI_CONTROLS</code> option + * is set, then the destination length may be less than + * <code>ubidi_getLength(pBiDi)</code>. + * If none of these options is set, then the destination length + * will be exactly <code>ubidi_getProcessedLength(pBiDi)</code>. + * + * @param options A bit set of options for the reordering that control + * how the reordered text is written. + * The options include mirroring the characters on a code + * point basis and inserting LRM characters, which is used + * especially for transforming visually stored text + * to logically stored text (although this is still an + * imperfect implementation of an "inverse Bidi" algorithm + * because it uses the "forward Bidi" algorithm at its core). + * The available options are: + * <code>#UBIDI_DO_MIRRORING</code>, + * <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code>, + * <code>#UBIDI_KEEP_BASE_COMBINING</code>, + * <code>#UBIDI_OUTPUT_REVERSE</code>, + * <code>#UBIDI_REMOVE_BIDI_CONTROLS</code> + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @return The length of the output string. + * + * @see ubidi_getProcessedLength + * @stable ICU 2.0 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_writeReordered(UBiDi *pBiDi, + UChar *dest, int32_t destSize, + uint16_t options, + UErrorCode *pErrorCode); + +/** + * Reverse a Right-To-Left run of Unicode text. + * + * This function preserves the integrity of characters with multiple + * code units and (optionally) combining characters. + * Characters can be replaced by mirror-image characters + * in the destination buffer. Note that "real" mirroring has + * to be done in a rendering engine by glyph selection + * and that for many "mirrored" characters there are no + * Unicode characters as mirror-image equivalents. + * There are also options to insert or remove Bidi control + * characters. + * + * This function is the implementation for reversing RTL runs as part + * of <code>ubidi_writeReordered()</code>. For detailed descriptions + * of the parameters, see there. + * Since no Bidi controls are inserted here, the output string length + * will never exceed <code>srcLength</code>. + * + * @see ubidi_writeReordered + * + * @param src A pointer to the RTL run text. + * + * @param srcLength The length of the RTL run. + * + * @param dest A pointer to where the reordered text is to be copied. + * <code>src[srcLength]</code> and <code>dest[destSize]</code> + * must not overlap. + * + * @param destSize The size of the <code>dest</code> buffer, + * in number of UChars. + * If the <code>UBIDI_REMOVE_BIDI_CONTROLS</code> option + * is set, then the destination length may be less than + * <code>srcLength</code>. + * If this option is not set, then the destination length + * will be exactly <code>srcLength</code>. + * + * @param options A bit set of options for the reordering that control + * how the reordered text is written. + * See the <code>options</code> parameter in <code>ubidi_writeReordered()</code>. + * + * @param pErrorCode must be a valid pointer to an error code value. + * + * @return The length of the output string. + * @stable ICU 2.0 + */ +U_CAPI int32_t U_EXPORT2 +ubidi_writeReverse(const UChar *src, int32_t srcLength, + UChar *dest, int32_t destSize, + uint16_t options, + UErrorCode *pErrorCode); + +/*#define BIDI_SAMPLE_CODE*/ +/*@}*/ + +#endif |